Mute processing apparatus and method for automatically sending mute frames

ABSTRACT

A mute processing method used in a multi-person communication system is provided. The method is capable of automatically sending mute frames when there are no sound inputs from terminals of the multi-person communication system. The method includes the steps of: collecting input signals from a microphone; calculating an energy level of the input signals within a time span; sending a mute frame if the energy levels of the input signals within previous continuous time spans are less than a predetermined energy level and the energy level of the input signals within the time span is still less than the predetermined energy level, otherwise, coding the input signals within the time span; and outputting the mute frame or coded signals. A related apparatus is also provided.

TECHNICAL FIELD

The present invention relates to mute processing apparatuses and methods, and particularly to a mute processing apparatus and method for automatically sending mute frames during a multi-person communication over a network.

GENERAL BACKGROUND

With the development of communication networks and the associated services, a multi-person communication has been introduced and regarded as one typical service in the communication networks, such as the Public Switched Telephone Network (PSTN) and the Voice Over Internet Protocol (VoIP) Network. Furthermore, the multi-person communication has been also pervasively applied in a network telephone conversation or a network TV conversation. Such multi-person communication can support multiple persons simultaneously to communicate, and deliver speech data from broadcaster(s) to the listeners.

In order to provide a friendly communication environment, it is critical for the multi-person communication to utilize system resources to reduce delay, namely to deliver the speech data to each person as soon as possibly. With respect to the delay problem, controlling a transferring amount of the speech data is an effective method to solve the delay problem. However, in the currently multi-person communication, it transfers all speech data regardless of sound data or soundless data over the communication network. In other words, the soundless data is send over the communication network as well as the sound data. As a result, the soundless data increases a loading of the communication network and the transferring amount of the speech data. Consequently, a delay phenomenon may appear due to the unnecessary soundless data, therefore, a service quality of the multi-person communication system may be weaken due to the delay phenomenon.

What is needed, therefore, is a mute processing apparatus and method used in the multi-person communication system, which can automatically send mute frames when there are no sound inputs from terminals of the multi-person communication system without sending unnecessary soundless data, thereby reducing the transferring amount of the speech data due to rather less sizes of the mute frames as compared to the soundless data.

SUMMARY

A mute processing apparatus is provided. The apparatus is capable of automatically sending mute frames when persons don't talk or keep mute during a multi-person communication over a network. The apparatus mainly includes a sampling unit, an energy calculating unit, a coding unit, a processing unit, and an output unit. The sampling unit is for collecting input signals from a microphone. The energy calculating unit is for calculating an energy level of input signals within a time span. The coding unit is for coding the input signals within the time span. The processing unit is for sending a mute frame within the time span if the energy levels of the input signals within previous continuous time spans are less than a predetermined energy level and the energy level of the input signals within the time span is still less than the predetermined energy level, otherwise, controlling the coding unit to code the input signals within the time span. The output unit is for outputting the mute frame from the processing unit or coded signals from the coding unit.

A mute processing method is also provided. The method includes the steps of: (a) collecting input signals from a microphone; (b) calculating an energy level of input signals within a time span; (c) sending a mute frame if the energy levels of the input signals within previous continuous time spans are less than a predetermined energy level and the energy level of the input signals within the time span is still less than the predetermined energy level, otherwise, coding the input signals within the time span; and (d) outputting the mute frame or coded signals.

Other advantages and novel features will be drawn from the following detailed description with reference to the attached drawing, in which:

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic diagram of a hardware infrastructure of a mute processing apparatus for automatically sending mute frames during a multi-person communication over a network in accordance with a preferred embodiment of the present invention; and

FIG. 2 is a flowchart of a preferred mute processing method for automatically sending mute frames during a multi-person communication over a network by utilizing the apparatus of FIG. 1.

DETAILED DESCRIPTION

FIG. 1 is a schematic diagram of a hardware infrastructure of a mute processing apparatus (hereinafter, “the apparatus”) in accordance with a preferred embodiment of the present invention. The apparatus is used in a multi-person communication system, and preferably, is incorporated into each terminal of the multi-person communication system. The apparatus is capable of automatically sending mute frames when there are no sound inputs on any ends during the multi-person communication, thereby reducing a loading of a network responsible for transmitting data throughout the terminals. The apparatus includes a sampling unit 10, an energy calculating unit 11, a coding unit 12, a counter 13, an output unit 14, a processing unit 15, a volatile storage unit 16, and a non-volatile storage unit 17.

The sampling unit 10 is for collecting input signals from a microphone (not shown) connected to the apparatus.

The energy calculating unit 11 is for calculating an energy level of the input signals within a time span. That is, the energy calculating unit 11 regards the input signals within one time span as a sound unit, and calculates the energy level of each sound unit.

If the energy level of the sound unit is equal to or greater than a predetermined energy level, that means the terminal of the multi-person communication is inputting sound within the time span, therefore, a speech coding operation is required on the sound unit input signals to obtain coded signals to be sent out over the network.

If energy levels of several continuous sound units are a combination consisting of energy levels greater than (equal to) and less than the predetermined energy, that means the terminal of the multi-person communication may have one or more input pauses over several continuous time spans, therefore, the speech coding operation is required on each sound unit input signals over the several continuous time spans to obtain coded signals to be sent out over the network.

If the energy levels of several previous continuous sound units are less than the predetermined energy level, and the energy level of a following sound unit is still less than the predetermined energy level, that means there is no sound input from the terminal of the multi-person communication within the several previous continuous time span and the time span of the following sound unit, therefore, a mute frame is sent within the time span of the following sound unit instead of performing a speech coding operation on the following sound unit input signals.

The coding unit 12 is for performing the speech coding operation on the input signals within the time span, that is, for coding the sound unit input signals. The counter 13 provides a value for indicating a count of continuous sound units whose energy level is less than the predetermined energy level. Furthermore, an initial value of the counter 13 is zero. The output unit 14 is for outputting coded signals from the coding unit 13 or the mute frame.

The processing unit 15 is for controlling the components of the apparatus, i.e., the sampling unit 10, the energy calculating unit 11, the coding unit 12, the counter 13, the output unit 14, the volatile storage unit 16, and the non-volatile storage unit 17.

The processing unit 15 resets the value of the counter 13 as the initial value and simultaneously signals the coding unit 12 to perform the speech coding operation on the sound unit input signals within the time span, if the energy level of the sound unit is equal to or greater than the predetermined energy level.

The processing unit 15 also signals the coding unit 12 to perform the sound coding operation on each sound unit input signals within the several continuous time spans, if the energy levels of several continuous sound units are the combination of energy levels greater than (equal to) and less than the predetermined energy level, or the energy levels of several continuous sound units are less than the predetermined energy level. The processing unit 15 further increases the value of the counter 13 by one while simultaneously performing the speech code operation on each sound unit input signals.

Moreover, the processing unit 15 sends the mute frame instead of performing the sound coding operation on the sound unit input signals and increasing the value of the counter 13, if the energy levels of several previous continuous sound units are less than the predetermined energy level and the energy level of the following sound unit is still less than the predetermined energy level. That is, if the value of the counter 13 is equal to a predetermined value and the energy level of the following sound unit is less than the predetermined energy level, the processing unit 15 signals the output unit 14 to output the mute frame.

Therefore, in the case when the value of the counter 13 equals to the predetermined value and the energy levels of the several continuous sound units are still less than the predetermined energy, the apparatus simply sends the mute frame within each corresponding time span of the sound units. Otherwise, the apparatus sends coded signals within each corresponding time span. Because a size of the mute frame is rather less than a size of the sound unit coded signals, a transferring amount of the mute frame is consequentially less than a transferring amount of the sound unit coded signals. As a result, a loading of the network is available to be reduced due to less transferring amounts of mute frames, thereby eliminating delay phenomena.

Additionally, the volatile storage unit 16 is for storing the input signals of each sound unit and the energy level of the input signals of each sound unit. The non-volatile storage unit 17 is for storing the predetermined energy level and the predetermined value.

FIG. 2 is a flowchart of a preferred mute processing method for automatically sending mute frames during the multi-person communication over the network by utilizing the apparatus of FIG. 1. In step S200, the sampling unit 10 collects the input signals from the microphone connected thereto. In step S201, the energy calculating unit 11 calculates the energy level of the input signals within a current time span. In step S202, the processing unit 15 determines whether the energy level calculated is less than the predetermined energy level.

If the energy level calculated is not less than the predetermined energy level, in step S203, the processing unit 15 resets the value of the counter 13. In step S204, the coding unit 12 performs the speech coding operation on the current sound unit input signals, and the output unit 14 sends out the coded signals from the coding unit 12 over the network. In step S205, the energy calculating unit 11 calculates the energy level of the input signals within a following time span, and the procedure goes to step S202 described above.

If the energy level calculated is less than the predetermined energy level, in step S206, the processing unit 15 determines whether the value of the counter 13 is less than the predetermined value.

If the value of the counter 13 is less than the predetermined value, in step S207, the coding unit 12 performs the speech coding operation on the current sound unit input signals, and the output unit 14 sends out the coded signals from the coding unit 12 over the network. In step S208, the processing unit increases the value of the counter 13 by one. In step S209, the energy calculating unit 11 calculates the energy level of the input signals within a following time span, and the procedure goes to step S202 described above.

If the value of the counter 13 is not less than the predetermined value, that means there is no sound input from the terminal of the multi-person communication within the current time span, in step S210, the processing unit 15 signals the output unit 14 to output the mute frame over the network, thereby reducing the loading of the network. In step S211, the energy calculating unit 11 calculates the energy level of the input signals within a following time span. In step S212, the processing unit 15 determines whether the energy level calculated is less than the predetermined energy level. If so, that means there is still no sound input from the terminal of the multi-person communication, and the procedure goes to step S211 described above to output the mute frame again over the network. If not, that means the terminal of the multi-person communication is inputting sound, and the procedure goes to step S203 described above.

Although the present invention has been specifically described on the basis of a preferred embodiment and preferred method thereof, the invention is not to be construed as being limited thereto. Various changes or modifications may be made to the embodiment and method without departing from the scope and spirit of the invention. 

1. A mute processing apparatus for automatically sending mute frames during a multi-person communication over a network, the apparatus comprising: a sampling unit, for collecting input signals from a microphone; an energy calculating unit, for calculating an energy level of the input signals within a time span; a coding unit, for coding the input signals within the time span; a processing unit, for sending a mute frame within the time span if the energy levels of the input signals within previous continuous time spans are less than a predetermined energy level and the energy level of the input signals within the time span is still less than the predetermined energy level, otherwise controlling the coding unit to code the input signals within the time span; and an output unit, for outputting the mute frame from the processing unit or coded signals from the coding unit.
 2. The apparatus according to claim 1, further comprising a counter for providing a value indicating a count of continuous time spans in which the energy levels are less than the predetermined energy level.
 3. The apparatus according to claim 2, wherein the processing unit sends the mute frame within the time span, if the value of the counter is equal to a predetermined value and the energy level of the input signals within the time span is less than the predetermined energy level.
 4. The apparatus according to claim 3, wherein the value of the counter increases by one if the energy level of the input signals within the time span is less than the predetermined energy level.
 5. The apparatus according to claim 4, wherein the processing unit resets the value of the counter if the energy level of the input signals within the time span is equal to or greater than the predetermined energy level.
 6. The apparatus according to claim 5, further comprising a volatile storage unit for storing the input signals of each time span and the energy level of the input signals of each time span.
 7. The apparatus according to claim 6, further comprising a non-volatile storage unit for storing the predetermined energy level and the predetermined value.
 8. A mute processing method for automatically sending mute frames during a multi-person communication over a network, the method comprising the steps of: collecting input signals from a microphone; calculating an energy level of input signals within a time span; sending a mute frame if the energy levels of the input signals within previous continuous time spans are less than a predetermined energy level and the energy level of the input signals within the time span is still less than the predetermined energy level, otherwise, coding the input signals within the time span; and outputting the mute frame or coded signals.
 9. The method according to claim 8, further comprising the step of: providing a counter with a value indicating a count of continuous time spans in which the energy levels are less than the predetermined energy level.
 10. The method according to claim 9, wherein the sending step further comprising the step of: sending the mute frame if the value of the counter is equal to a predetermined value and the energy level of the input signals is less than the predetermined energy level.
 11. The method according to claim 10, further comprising the step of: increasing the value of the counter by one if the energy level of the input signals within the time span is less than the predetermined energy level.
 12. The method according to claim 11, further comprising the step of: resetting the value of the counter if the energy level of the input signals within the time span is equal to or greater than the predetermined energy level.
 13. The method according to claim 12, further comprising the step of: providing a volatile storage unit and a non-volatile storage unit, the volatile storage unit for storing the input signals of each time span and the energy level of the input signals of each time span, and the non-volatile storage unit for storing the predetermined energy level and the predetermined value. 